The objective of this study is to investigate the applicability of a radiation therapy treatment planning program based on a cell kinetics model to a well known experimental tumor and normal tissue system. The first phase of this project is centered on theoretical and numerical analysis of the available experimental data on C3H murine mammary tumors and C3H skin. The kinetic models used in the program and the procedures used in the derivation of kinetic models used in the program and the procedures used in the derivation of kinetic parameters will be tested. An optimization program for treatment planning will be developed. In the second phase a limited number of experiments will be performed to test the theoretical and numerical results.